NAME

SYNOPSIS

To compile this capability into your kernel place the following line in your kernel
configuration file:
devicecpufreq

DESCRIPTION

The est interface provides support for the Intel Enhanced Speedstep Technology.
Note that est capabilities are automatically loaded by the cpufreq(4) driver.

LOADERTUNABLES

The est interface is intended to allow cpufreq(4) to access and implement Intel Enhanced
SpeedStep Technology via acpi(4) and the acpi_perf interface accessors. If the default
settings are not optimal, the following sysctls can be used to modify or monitor est
behavior.
hw.est.msr_info
Attempt to infer information from direct probing of the msr. Should only be used in
diagnostic cases. (default 0)
hw.est.strict
Validate frequency requested is accepted by the cpu when set. It appears that this
will only work on single core cpus. (default 0)

DIAGNOSTICS

est%d:<EnhancedSpeedStepFrequencyControl>oncpu%d
Indicates normal startup of this interface.
est:CPUsupportsEnhancedSpeedstep,butisnotrecognized.est:cpu_vendorGenuineIntel,msr471c471c0600471cdevice_attach:est%dattachreturned6
Indicates all attempts to attach to this interface have failed. This usually indicates an
improper BIOS setting restricting O/S control of the CPU speeds. Consult your BIOS
documentation for more details.